Different hashes for nand.bin

Hi, is it normal for NAND backups to have different hashes? I dumped my NAND two times in a row and the MD5 for them is different.

Thanks

Same issue here, I have Bootmii installed on Boot2, just did two consecutive backups (correctly verify by BootMii)
Beyond Compare shows some differences between the two dumps...

IOS and the System Menu both write a surprising amount of data to flash every time you boot. This includes removing and recreating /tmp, removing and recreating /sys/launch.sys, etc. Several files are created that store state.

If you're bored, try an experiment:

* Boot BootMii (as IOS or boot2), make NAND backup. After verification completes, remove SD card, copy file to computer as nand1.bin
* Without rebooting, make another NAND backup. Copy to computer as nand2.bin
* Boot HBC from BootMii, then boot back in to BootMii (either by running BootMii from the HBC menu, or power off your Wii and the power back on. Make NAND backup, copy to computer as nand3.bin
* Boot System Menu from BootMii, then boot back into BootMii (whichever way). Make NAND backup, copy to computer as nand4.bin.

You can compare the 4 nand files with whatever you want on the computer, or you can try running (simulated) Restore in between each of the steps to see a nice graphical representation. You should see:

* nand1.bin and nand2.bin are byte-for-byte identical. BootMii does not write to NAND.
* nand2.bin and nand3.bin have several blocks different (plus most of the metadata blocks at the end). This is the result of IOS's changes to the NAND as part of one normal boot.
* nand3.bin and nand4.bin have even more differences. This is the result of IOS changes + System Menu changes, even without running any channels or playing any games.

So, while you're still in the same session of BootMii for either IOS or boot2, there is no NAND writing whatsoever by any other part of the system (i.e. BootMii takes over completely)? Then, you should always have an identical NAND as long as you stay in the same BootMii session, correct?

Also, what would happen if you booted into boot2 BootMii, immediately turned off after creating nand1.bin and then re-entered BootMii boot2 after reboot to make nand2.bin. Does the Wii write to NAND before BootMii is invoked?

Would the different NAND hashes be the reason for my Wii acting so erratically on boot up?

I really cannot understand why sometimes it'll show "System Files Corrupt" and others it will boot normally while other times it will freeze at the 'Health and Safety' warning screen.

The differences in the NAND hashes are the only reason that I can think of.